Dear fsler,
I have questions about my 2x2 ANOVA interaction. I have two main effects: diagnosis group (patient and control ) and age (young and old). There are 2 subjects in each subgroup which makes 8 subjects in total. The design matrix of ANOVA looks like following
age diagnosis interaction mean
1 1 1 1
1 1 1 1
1 -1 -1 1
1 -1 -1 1
-1 1 -1 1
-1 1 -1 1
-1 -1 1 1
-1 -1 1 1
contrast:
F1 F2 F3
C1 1 0 0 0 X
C2 0 1 0 0 X
C3 0 0 1 0 X
C4 -1 0 0 0
C5 0 -1 0 0
C6 0 0 -1 0
The significant brain activities was found on all three F contrasts which means significant brain activity between age, diagnosis and age by diagnosis interaction. As interaction between two main effect showed significant in my model, in normal statistic test, I then need to check post hoc to explore one main effect according to each level of another main effect. I would like to know how can I achieve this in fsl?
When I checked the t-test results: C1-C6 there are only C4 showed significant brain activities. Should not C3 and C6 be significant?
bw,
Joyce
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